Closure for sprinklers and nozzles with heat activation

ABSTRACT

Closure for sprinklers and nozzles with heat activation for use in fire fighting, comprising a nozzle body ( 1 ) and an outlet channel ( 11 ) which is kept tightly closed by means of a cover ( 5 ). The cover ( 5 ) is detachably connected to the nozzle body ( 1 ) and detaches in case of fire. At least one of the fastenings between the cover ( 5 ) and the nozzle body ( 1 ) is a releasable arrangement ( 6 ) and at least one other is a connection ( 7 ). The heat-sensitive element is integrated in the releasable arrangement ( 6 ) or acts thereon so that the releasable arrangement ( 6 ) is detached when the heat-sensitive element is released. The forces on the cover ( 5 ) are distributed between the detachable assembly ( 6 ) and the joint ( 7 ) so that the detachable assembly ( 6 ) carries only a fraction of these forces.

The present invention relates to a closure for sprinklers and nozzleswith heat activation for use in the field of fire fighting, according tothe preamble of claim 1.

Most fire protection systems, for example sprinkler systems inbuildings, are automatically activated by heat-sensitive elements in theevent of a fire. This ensures high reliability, as they react directlyto the heat generated by the fire and are independent of any externalalarm signal or human action. Common heat sensitive elements are, forexample, fusible elements (see e.g. EP 1515780) or frangible glass bulbs(see e.g. U.S. Pat. No. 9,573,007). A major disadvantage of thesedevices is that they are only activated after the room air has beenheated by the fire and the heat-sensitive element is subsequently heatedby the heated room air. In the meantime, decisive minutes pass duringwhich the fire can develop and spread. In addition, dangerous smokeformation can already take place in the start-up phase, before the firereally starts, which should be fought as quickly as possible with awater mist for example. There are methods that practically enableimmediate fire detection, e.g. by means of smoke sensors. In EP 2038018,a closure for sprinklers and nozzles with heat activation is provided,whereby a smoke sensor or thermostat enables rapid fire detection. Thenozzle is closed with a cover plate firmly connected to the nozzle bodyby means of a fusible element. In the event of fire, the roomtemperature and the temperature of the fusible elements increase untilthe fusible elements melt, the cover plate falls away and the nozzle isopened. Parallel to this, the fusible elements are arranged on heatingelements which are controlled by the smoke sensor or the thermostat. Ifthe sensors report a fire, the fusible elements can be actively fusedwith the heating elements and the nozzle can thus be opened long beforethe passive fusion of the fusible elements due to the heated room air.Such systems thus combine two parallel activation methods: early, activeactivation by controlled heating after fire detection by sensors and, ifthis fails, passive activation by the heat generated by the fire.Another advantage of the device according to EP 2038018 is the compactdesign of the closure which hardly protrudes from the nozzle body and istherefore quite easy to integrate in a ceiling or wall. In contrast,conventional sprinklers with frangible glass bulbs (see e.g. U.S. Pat.No. 9,573,007) always have a length of several centimetres.

In practice, however, it has been shown that the melting temperature ofthe fusible elements can change over the years. Responsible for this isthe gradual deformation and change in the material structure of thefusible element due to creep caused by the constant tension it is under.For example, the fusible links in EP 2038018 carry both the force of thestructural part under tension and the compressive force of theextinguishing agent under pressure. During creep, the temperature andits fluctuations in the monitored room also play an important role: forexample, the deformation of the fusible elements is significantlyaccelerated at room temperatures of over 30° C. This can cause permanentdeformation of the fusible elements over the years and change themelting temperature of the fusible element. After several years, themelting point can be higher than originally intended, so that thefusible element responds later, but it can also be lower, so that thefusible element responds earlier. Both cause damage that was originallyintended to be avoided with the use of such devices. In contrast,breakable glass bulbs are reliable and stable heat-sensitive elementsand besides, they are available on the market in various standardversions with different triggering temperatures.

The object of the present invention is to improve a closure forsprinklers and nozzles with heat activation according to EP 2038018 insuch a way that the compact structure and the two parallel activationmethods (active by controlled activation and passive by the heatgenerated by the fire) are retained, but the activation mechanism isimproved in such a way that the reliability, stability and invariabilityof the activation temperature of the heat-sensitive element isguaranteed.

This object is achieved by a closure for sprinklers and nozzles withheat activation having the features of claim 1. Further features andembodiments are apparent from the dependent claims and their advantagesare explained in the following description.

THE DRAWINGS SHOW

FIG. 1a Closure for sprinklers and nozzles with flared outlet opening

FIG. 1b Closure for sprinklers and nozzles with deflector plate

FIG. 1c Closure for sprinklers and nozzles with pre-tensioning screw

FIGS. 2a-d Detail of the releasable arrangement

FIGS. 3a-c Detail of the connection

FIG. 4 Closure for sprinklers and nozzles with heat activation by afrangible glass bulb

FIG. 5 Top view of nozzle with heat activation by a frangible glass bulb

FIGS. 6a-b Bayonet groove

FIG. 7 Closure for sprinklers and nozzles with housing part

The figures show possible embodiments which are explained in thefollowing description.

The presented closure for sprinklers and nozzles with heat activation issuitable for use with water mist nozzles and/or with sprinklers. Thenozzle consists of a nozzle body 1 which can be connected to anextinguishing agent supply 2 of a fire protection system and arranged ona ceiling 3 or wall 3 of a building (FIGS. 1a-c ). The nozzle body 1 hasan outlet channel 11 through which the extinguishing agent flows out atpressure and speed during use. The diameter and profile of the outletchannel 11 is adapted to the pressure present in the fire protectionsystem, to the speed desired for extinguishing and to the desireddistribution of the extinguishing agent. Advantageously, the outletchannel 11 has a widened outlet opening (Figure la) or is provided witha fixed or extendable deflector plate (FIG. 1b ). In the waitingposition, the outlet channel 11 is tightly closed by a seal 4 which ispressed against the outlet opening of the outlet channel 11 by means ofa cover 5 and is held in this closed position. The seal 4 can bepre-tensioned with a pre-tensioning screw 8 or with another suitablemechanism. In the embodiment of FIG. 1c , the seal 4 is connected to thecover 5 via a pre-tensioning screw 8 in such a way that by turning thepre-tensioning screw 8, the cover 5 and the seal 4 are spread apart andthe seal 4 is pressed against the outlet opening of the outlet channel11 and pre-tensioned. The cover 5 is detachably connected to the nozzlebody 1 and is detached from it in the event of a fire, after which theseal 4 is washed away due to the pressure of the extinguishing agent inthe fire protection system and thus the nozzle is put into action.

The core of the invention is the method of fastening and the releasemechanism of the cover 5, which is fastened to the nozzle body 1 in sucha way that the heat-sensitive element does not have to carry thecomplete pressure forces of the compressed seal 4 and of the pressurisedextinguishing agent of the extinguishing system in the waiting position,but only part of it. In this case, the heat-sensitive element can be putunder less pressure or tension by means of an actuating element, e.g. aspring or a magnet, in order to release the closure. For closures with afusible element, this reduces the gradual deformation and change inmaterial structure of the fusible element due to creep. In general, itallows more freedom in positioning the heat-sensitive element in theclosure, providing nozzles with a much more compact design. For example,in closures using frangible glass bulbs, the glass bulb can be orientedat a right angle to the axis of the exit channel 11 to provide aparticularly compact nozzle.

According to the invention, it is envisaged to attach the cover 5 to thenozzle body 1 at at least 2 points, for example diametrically oppositein the case of a round cover 5 (FIGS. 1a-c ). At least one of thefastenings between the cover 5 and the nozzle body 1 is a releasablearrangement 6 and at least one other fastening between the cover 5 andthe nozzle body 1 is a connection 7. The heat-sensitive element isintegrated in the at least one releasable arrangement 6 in such a waythat the releasable arrangement 6 is released when the heat-sensitiveelement is activated, while the at least one connection 7 is merely anadditional fastening of the cover 5 to the nozzle body 1. The forcesexerted on the cover 5 are thus distributed between the at least onereleasable arrangement 6 and the at least one connection 7, so that eachreleasable arrangement 6 only has to absorb part of these forces. In theevent of fire, the release can be triggered both passively, i.e.directly due to the heat of the fire, or actively by selective heatingof the heat-sensitive element, the ejection of the cover 5 being carriedout according to the following steps:

-   -   1. When the heat-sensitive element is activated, the at least        one releasable arrangement 6 is detached, the cover 5 remaining        connected to the nozzle body 1 only by the at least one        connection 7;    -   2. Due to the pressurised extinguishing agent in the        extinguishing system, the seal 4 is ejected from the outlet        opening of the outlet channel 11 and the cover is ejected from        the nozzle body 1, thus bringing the nozzle into action;    -   3. As one side of the cover 5 is still retained by the        connection 7, the cover 5 moves around the connection 7;    -   4. This movement causes the cover 5 to fall out of the        connection 7 as it passes a certain angle, which can also be        very small, so that the cover 5 is then completely detached from        nozzle body 1;    -   5. The seal 4 is pushed away by the jet of extinguishing agent        together with the cover 5, so that the operation of the nozzle        is not hindered and no “shadow” is caused in the spray pattern.

It is important that the releasable arrangements 6 and the connection 7are arranged in such a way that the detachment of the releasablearrangement 6 allows the mentioned movement of the cover 5 away from thenozzle body, until the complete detachment of the same.

Possible embodiments of the releasable arrangement 6 and of theconnection 7 are explained in more detail in the following part withreference to FIGS. 2a-d and 3a -c.

FIGS. 2a-b show possible embodiments of the releasable arrangement 6comprising a fusible element 61 or an explosive 63. The fusible element61 or explosive 63 establishes the connection between the cover 5 andthe nozzle body 1. The fusible element 61 may be a metal alloy, aplastic or an adhesive. The chosen material must ensure the firmconnection between the nozzle body 1 and the cover 5 only against afraction of the forces of the seal 4 under tension and of theextinguishing agent under pressure. Furthermore, the material must meltwithin a relatively narrow temperature range that can be reliablydefined over the years so that the fusible element melts completelywithin as short a time as possible when the lower limit of thistemperature range is reached. In the event of fire, the fusible element61 is passively heated by the heat generated by the fire until it meltsand the cover 5 detaches. To actively trigger the closure, the inventionprovides for actively heating the fusible element 61 by means of acontrolled electrical resistance or induction heating element. Theresistive element may be the fusible element 61 itself if it is made ofconductive material. In an alternative embodiment, the controlledelectrical resistance or induction heating element is arranged adjacentto the fusible element 61 and the generated heat is transferred to thefusible element 61 by conduction or radiation.

FIG. 2c shows another embodiment of the releasable arrangement 6comprising a fastening element 62 and an explosive 63. The fasteningelement 62, for example a special screw or an adhesive, establishes theconnection between the cover 5 and the nozzle body 1. When the explosive63 is detonated, the cover 5 is detached from the nozzle body 1. Thiscan be done, for example, by breaking off the fastening element 62,which may have a predefined breaking point, or by locally destroying theedge of the cover 5. In the event of fire, the explosive 63 is passivelyheated by the heat generated by the fire until it spontaneouslydetonates. To actively trigger the closure, the explosive 63 may beactively heated by means of a controlled electrical resistance orinduction heating element. Alternatively, the electrical element couldtrigger the explosive 63 with an electrical pulse as in an airbagigniter or with a spark.

FIG. 2d shows a further embodiment of the releasable arrangement 6comprising a latch 65 and a fusible element or an explosive 63. Thelatch 65 is slidable in the cover 5 between two positions: a closedposition in which the front end of the latch 65 abuts a first abutmentof the nozzle body 1 or engages in a first recess 12 of the nozzle body1, and an open position in which the front end of the latch 65 does notengage in the first recess 12. The cover 5 has an inner cavity 51 intowhich the rear part of the latch 65 engages. An actuating element 66acts on the latch 65 and on the cover 5 in such a way that the latch 65is always pressed in the direction of the open position. Depending onthe embodiment of the closure, a spring or a magnet can be used asactuating element 66. In the embodiment of FIG. 2d , for example, aspring 66 is arranged between a bulge of the latch and a wall of theinner cavity 51. In the waiting position, the latch 65 is held in theclosed position against the force of the actuating element 66 by meansof a fusible element 61 or of an explosive 63.

FIG. 3a shows a possible embodiment of the connection 7, whereby theedge of the cover 5 simply engages in a second recess 13 of the nozzlebody 1. This simple method of attachment firmly retains the cover 5 butdoes not prevent its ejection once the releasable arrangement 6 isdetached. To make it easier to attach the cover 5 to the nozzle body 1at any angle, the second recess 13 may simply be a circumferentialgroove 13.

FIGS. 3b-c show further possible embodiments of the connection 7,wherein the nozzle body 1 has a hook which engages in a recess in thecover 5.

In an alternative embodiment of the closure, the releasable arrangement6 comprises a latch 65 and a heat-sensitive element which is arranged inthe cover 5 behind the latch and holds the latch 65 in the closedposition. A fusible element 61 or an explosive 63 may be used as theheat sensitive element. If a frangible glass bulb 64 is used as theheat-sensitive element, this may be arranged in the horizontaldirection, i.e. at a right angle to the axis of the outlet channel 11,in order to save space and provide as compact an arrangement aspossible. The glass bulb 64 can be integrated in the nozzle body 1 or,as shown for example in FIG. 4, in the cover 5. This is particularlyadvantageous because the glass bulb 64 breaks when activated and thecover 5 is ejected anyway. In more complex arrangements, e.g. asprinkler with a deflector plate, certain parts of the arrangement canalso be extendable. It is advantageous for all arrangements if they areas compact and space-saving as possible.

In the embodiment according to FIG. 4, the connection 7 simply consistsof a second recess 13 in which an edge of the cover 5 engages. Thereleasable arrangement 6 comprises the glass bulb 64 and a latch 65which engages in a first recess 12. To make the cover 5 easier to attachto the nozzle body 1 at any angle, the first recess 12 and the secondrecess 13 may simply form two separate circumferential grooves 12, 13,or even a common circumferential groove 12/13. For easy attachment ofthe cover 5 and simultaneous pressing of the seal 4 against the outletchannel 11, the first and second recesses 12, 13 could also formbayonet-shaped grooves (FIGS. 6a-b ). The latch 65 is slidable in thecover 5 between two positions: a closed position in which the front endof the latch 65 engages in the first recess 12, and an open position inwhich the front end of the latch 65 does not engage in the first recess12. The cover 5 has an inner cavity 51 into which the rear part of thelatch 65 engages. An actuating element 66 acts on the latch 65 and onthe cover 5 in such a way that the latch 65 is always pressed in thedirection of the open position. Depending on the embodiment variant ofthe closure, a spring, a magnet or simply a weight can be used as theactuating element 66. In the embodiment variant of FIG. 4, for example,a spring 66 is arranged between a bulge of the latch and a wall of theinner cavity 51. In the waiting position, the latch 65 is held in theclosed position against the force of the actuating element 66 by meansof a heat-sensitive and frangible glass bulb 64. In the embodiment ofFIG. 4, the glass bulb 64 is arranged between a wall of the inner cavity51 and the rear end of the latch 65, thus preventing a movement of thelatch 65 from the closed position to the open position.

Another possible embodiment provides that the cover 5 is pre-assembledand integrated in a housing part 9, whereby this housing part 9 isdesigned in such a way that it can be easily attached to the nozzle body1. For example, it is possible to provide the housing part 9 with anexternal thread which can be screwed into the correspondingcounter-thread of the nozzle body 1 (FIG. 7).

Preferably, a common heat-sensitive and frangible glass bulb for firesprinklers available on the market can be chosen as the glass bulb 64.The glass bulb 64 ensures the passive activation of the closure: in theevent of fire, the room air and the glass bulb 64 are heated until theglass bulb 64 bursts when a defined temperature is exceeded. For theactive triggering of the closure, the glass bulb 64 is actively heatedby means of a controlled electrical resistance or induction heatingelement. The electrical resistance or induction element may be a coilwound around the glass bulb 64, or a rectilinear path attached to itssurface. In the preferred embodiment, the glass bulb is fully orpartially coated with a resistive heating material. This ensures alarger contact area between the heating material and the glass bulb 64,thus promoting heat conduction from the heating element to the glassbulb. As soon as the glass bulb 64 no longer holds the latch 65 in theclosed position, the actuating element 66 pulls it into the openposition. From this moment on, the cover 5 is tilted away from thenozzle body 1 by the pressure of the extinguishing agent in the outletchannel 11.

The energy required to heat/trigger the fusible element 61, theexplosive 63 and/or the glass bulb 64 originates either from an externalenergy source, e.g. via an electric line, or from a dedicated energysource, e.g. from an integrated battery. The heating of the heatsensitive element is controlled by an intelligent controller connectedto one or more fire sensors 14, for example a smoke sensor or athermostat. The intelligent controller is for example a microprocessoror a computer. In addition or instead, the intelligent controller mayalso receive an external fire alarm or instruction, for example from acentral control station. The intelligent control offers the possibilitythat sensors first trigger an alarm and only after a defined time doesthe nozzle actually react with extinguishing agent. For example, asensor triggers an alarm if toxic smoke endangers people withoutimmediately putting the nozzle and the entire extinguishing system intooperation and thus causing damage.

If some components (the energy source, the intelligent controller, thefire sensors 14 or the heat-sensitive element) are located in the cover5 and others in the nozzle body 1, the nozzle must be provided withmeans for establishing electrical contact between the nozzle body 1 andthe cover 5. In a possible embodiment of the invention, this electricalcontact is established on the one hand by the releasable arrangement 6and on the other hand by the connection 7. For this purpose, in theembodiment with glass bulb 64 in the cover 5, the second recess 13, thepart of the edge of the cover 5 engaging therein, the first recess 12and the latch 65 could comprise an electrically conductive material,consist of electrically conductive material or be coated withelectrically conductive material.

1. Closure for sprinklers and nozzles with heat activation, with anozzle body (1) and an outlet channel (11), wherein a seal (4) isarranged on the nozzle body (1) above the outlet channel (11), whichseals off the outlet channel (11), wherein the seal (4) is pressedagainst the outlet channel (11) by a cover (5) and is held in the closedposition, wherein the cover (5) is detachably fastened to the nozzlebody (1) and can be actively or passively removed in the event of fire,characterised in that the cover (5) is connected to the nozzle body (1)by at least two fastenings, a first fastening is a releasablearrangement (6) and a second fastening is a connection (7) around whichthe cover (5) is movable, wherein the releasable arrangement (6)comprises at least one heat-sensitive element and is released uponactive or passive activation of the heat-sensitive element.
 2. Closureaccording to claim 1, characterised in that the cover (5) falls out ofthe connection (7) after a certain angle of movement and is thuscompletely detached from the nozzle body (1).
 3. Closure according toclaim 1, characterised in that the releasable arrangement (6) comprisesa fusible element (61) which connects the cover (5) to the nozzle body(1), fuses in the event of fire and detaches the cover (5) from thenozzle body (1).
 4. Closure according to claim 1, characterised in thatthe detachable assembly (6) comprises a fastening element (62) and anexplosive (63) which is detonated in the event of fire and detaches thecover (5) from the nozzle body (1).
 5. Closure according to claim 4,characterised in that the fastening element (62) is a special screw witha predefined breaking point or an adhesive.
 6. Closure according toclaim 1, characterized in that the releasable assembly (6) comprises aheat-sensitive and frangible glass bulb (64).
 7. Closure according toclaim 6, characterized in that the glass bulb (64) is arranged in thecover (5) substantially at right angles to the axis of the outletchannel (11).
 8. Closure according to claim 7, characterised in that thereleasable assembly (6) comprises a latch (65) movable in the cover (5)between two positions: a closed position in which the front end of thelatch (65) engages in a first recess (12) of the nozzle body (1) orabuts against a first abutment of the nozzle body (1), and an openposition in which the front end of the latch (65) does not engage in thefirst recess (12) or does not abut against the first abutment. 9.Closure according to claim 8, characterized in that the cover (5)comprises an actuating element (66) which acts on the latch (65) and onthe lid (5) in such a way that the latch (65) is always pushed or pulledtowards the open position, wherein in the waiting position, the glassbulb (64) holds the latch (65) in the closed position against the forceof the actuating element (66).
 10. Closure according to claim 3 or 4 or6, characterised in that for active activation of the nozzle, theheat-sensitive element is actively heated by means of a controlledelectrical resistance or induction heating element.
 11. Closureaccording to claim 10, characterized in that the active heating of theheat sensitive element is controlled by an intelligent controller. 12.Closure according to claim 11, characterised in that the intelligentcontroller is connected or can communicate with one or more fire sensors(14) and/or with an external control station from which the intelligentcontroller receives fire alarms and/or instructions.
 13. Closureaccording to claim 1, characterised in that the heat sensitive elementis only activated passively and a second heat sensitive element is onlyactivated actively.